I have a 84 Tropry I am working on, it has a battery on each side of Transom upper storge box's & its wired for a third battery on the starboard side lower storage compartment aginst the Transom below the Deck,there is no mounting brackets or battery box ,should the battery set flush on the bottom of the hull or should it be elevated & the termenals be level are above the Deck height & whats a good way to mount the battery Thanks Ken